What Is .NET?
When .NET was announced in late 1999, Microsoft positioned the technology as a platform for building and consuming Extensible Markup Language (XML) Web services. XML Web services allow any type of application, be it a Windows- or browser-based application running on any type of computer system, to consume data from any type of server over the Internet. The reason this idea is so great is the way in which the XML messages are transferred: over established standard protocols that exist today. Using protocols such as SOAP, HTTP, and SMTP, XML Web services make it possible to expose data over the wire with little or no modifications to your existing code.Figure 1.1 presents a high-level overview of the .NET Framework and how XML Web services are positioned.
Figure 1.1. Stateless XML Web services model.

Since the initial announcement of the .NET Framework, it's taken on many new and different meanings to different people. To a developer, .NET means a great environment for creating robust distributed applications. To an IT manager, .NET means simpler deployment of applications to end users, tighter security, and simpler management. To a CTO or CIO, .NET means happier developers using state-of-the-art development technologies and a smaller bottom line. To understand why all these statements are true, you need to get a grip on what the .NET Framework consists of, and how it's truly a revolutionary step forward for application architecture, development, and deployment.